| disease | Too Much Water |
| alias | Water Intoxication, Dilutional Hyponatremia |
It refers to the excessive intake or input of water by the body, leading to water retention, a decrease in blood osmotic pressure, and an increase in circulating blood volume, also known as "water intoxication" or dilutional hyponatremia. Water intoxication occurs rarely and only when there is excessive secretion of antidiuretic hormone or impaired renal function, combined with excessive water intake or excessive intravenous fluid administration, resulting in water accumulation in the body and causing water intoxication.
bubble_chart Etiology
Excessive intake of water or excessive fluid infusion. Even if a normal person consumes a large amount of water, under the regulatory effects of the nervous, endocrine systems, and kidneys, the kidneys can still excrete the water to maintain water balance. However, in cases of excessive antidiuretic hormone secretion or renal insufficiency, excessive water intake or excessive fluid infusion can prevent the kidneys from effectively excreting water, leading to water retention in the body and resulting in water intoxication. During water intoxication, the extracellular fluid volume increases, serum sodium concentration decreases, and osmotic pressure drops. The osmotic pressure of intracellular fluid is relatively higher, causing water to shift into the cells. As a result, both intracellular and extracellular fluid volumes expand, leading to cerebral edema and pulmonary edema.
bubble_chart Clinical Manifestations
It can be divided into acute and chronic water intoxication.
1. Acute water intoxication: The onset is rapid. Due to the increase in intracellular and extracellular fluid volume, the cranial cavity and spinal canal lack elasticity, leading to symptoms of increased intracranial pressure caused by brain cell edema, such as headache, aphasia, mental confusion, disorientation, drowsiness, agitation, delirium, and even unconsciousness. Further progression may result in brain herniation, potentially leading to respiratory and cardiac arrest.
2. Chronic water intoxication: Symptoms are generally not obvious and are often masked by the symptoms of the primary disease. There may be weakness, nausea, vomiting, drowsiness, etc., along with weight gain and pale, moist skin.Based on medical history and clinical manifestations, a diagnosis can generally be made. Due to hemodilution, laboratory tests may reveal decreased red blood cell count, hemoglobin, hematocrit, and plasma protein levels, as well as reduced serum sodium and chloride measurements.
bubble_chart Treatment Measures
Prevention is better than cure. For individuals with renal insufficiency or those prone to excessive antidiuretic hormone secretion, strict control of water intake is essential to prevent water intoxication. Once water intoxication occurs, Grade I patients can recover spontaneously by stopping water intake and allowing the body to excrete excess water. For severe cases, immediate water restriction is necessary, along with the use of diuretics to enhance water excretion. Osmotic diuretics, such as 20% mannitol or 25% sorbitol (0.2L), administered via rapid intravenous drip, or loop diuretics like furosemide and ethacrynic acid, can be used to reduce cerebral edema and increase water excretion. Additionally, a 5% hypertonic saline solution can be administered intravenously to rapidly alleviate intracellular edema and improve symptoms. However, for patients with oliguria or anuria due to acute renal failure, diuretics and large doses of hypertonic saline are not only ineffective but also risk increasing circulatory load and should be avoided. In such cases, apart from stopping water intake, artificial dialysis may be employed.
